Sure, this book does well in explaining the physiological process of sleep, spleep apnea, and other sleeping problems that are not related to the many types of insomnia. It also reviews the things you already know about sleep. If you are searching for information on how deal with insomnia or other general sleeping disorders, this book is of little help.
The title is a tad misleading. It suggests lightweight content. The book is indeed concise and easy-to-follow, but it also solidly professional and rigorous. Of the three books on improving sleep that I read when I was experiencing sleep problems this past winter, All I Want Is A Good Night's Sleep helped me the most. It provides two effective strategies for incrementally improving one's sleep, one night at a time.